A commercially available device suppresses photic driving: implications for EEG recording.

Intermittent photic stimulation (IPS) is an activation procedure routinely performed during EEG. The EEG response may consist in physiological photic driving (PPD) or in photoparoxysmal response (PPR). Sometimes, the distinction between PPR and PPD can be challenging, especially in case of PPR limited to posterior regions (Waltz type 1 or 2). A commercially available device, namely Zeiss Clarlet F133 lenses (ZEISS lenses), can suppress PPR, while its influence on PPD is still unknown. This study aims to test the effect of ZEISS lenses on PPD at different flash frequencies. We prospectively collected all consecutive EEGs showing PPD to IPS, performed both with eyes open and closed at stimulation frequencies between 3 and 24 Hz. When PPD was present, IPS with ZEISS lenses was performed. We analyzed the presence of PPD without and with lenses by means of McNemar's test We included 97 EEGs showing PPD. This response was more commonly obtained at flash frequencies between 6 and 12 Hz. The use of ZEISS lenses significantly decreased the proportion of subjects showing PPD at each frequency (p < 0.001 for all comparisons). ZEISS lenses significantly reduce the proportion of subjects showing PPD at all stimulus frequencies, regardless of eye opening or closure. Physicians should consider that ZEISS lenses do not allow distinction between PPD and PPR. The effect of ZEISS lenses on PPR and on PPD suppression suggests that these two phenomena derive from similar mechanisms involving the entrainment of neural oscillators within the visual cortex.

Gestural automatisms during syncope related to cervical malignancy.

Cervical malignancies are a rare but well-known cause of syncope. Gestural automatisms during syncope have only rarely been reported. We describe a patient presenting with bimanual automatisms during syncopal episodes caused by parapharyngeal carcinoma involving the right laterocervical region. Ictal phenomenology was strongly suggestive of focal seizures and only video-polygraphic recording including EEG and ECG allowed the correct diagnosis to be established. Syncopal episodes ceased after partial removal of the mass. Although gestural automatisms in the context of a sudden spell with loss of consciousness are strongly suggestive of focal (mainly frontal or temporal) seizures, the diagnosis of syncope must be taken in account and confirmed or excluded by appropriate neurophysiological investigations.

The Natural History of Epilepsy in 163 Untreated Patients: Looking for "Oligoepilepsy".

The clinical evolution of untreated epilepsy has been rarely studied in developed countries, and the existence of a distinct syndrome characterized by rarely repeated seizures (oligoepilepsy) is debated. The aim of this study is to assess the natural history of 163 untreated patients with epilepsy in order to evaluate whether oligoepilepsy retains specific features. We retrospectively evaluated 7344 patients with ≥2 unprovoked seizures. INCLUSION CRITERIA: sufficient anamnestic/EEG data, disease duration ≥10 years, follow-up ≥3 years. EXCLUSION CRITERIA: psychogenic seizures, natural history of disease <5 years. The 163 included subjects were divided into 2 groups according to seizure frequency: oligoepilepsy (≤1/year; 47 subjects) and controls (>1/year; 116 subjects). We also evaluated seizure frequency during the natural history. There were no differences between groups regarding duration of natural history, family history of epilepsy/febrile seizures, interictal EEG. Subjects with oligoepilepsy differed from controls in terms of sex (females 38% vs. 58%, p = 0.03) and drug resistance (6% vs 28%; p = 0.003). Juvenile myoclonic epilepsy was more frequent in controls (9.5% vs 0%, p = 0.04). Patients with oligoepilepsy, differently from controls, had stable seizure frequency. Oligoepilepsy represents a favourable evolution of different epileptic syndromes and keeps a stable seizure frequency over time.